KLK3 and posterior cortical atrophy: Immunofluorescence (IF) analysis of AR and PSA proteins in 11 untreated primary patient tumors (HPCa; Supplementary Table 2) directly supports this premise as the 4 subpopulations of PCa cells could be identified in all samples, although, as expected, the AR+PSA+ PCa cells represented the major subpopulation (Figure 2A–2B; Supplementary Figure 1 and 2).